A conventional three-dimensional image display device captures two images, which will be viewed by the viewer with his or her right and left eyes, using two cameras corresponding to the eye and then superposes those two images on a stereoscopic display. With such a display device, however, if the interval between the two cameras is significantly different from the interval between the viewer's eyes, he or she will find the resultant stereoscopic image unnatural, which is a problem.
Thus, to overcome such a problem, Patent Document No. 1 discloses a method for making a correction on one of the two images captured by those two cameras on the right- and left-hand sides (which will be simply referred to herein as “right and left cameras”) using the image captured by the other camera so that the amount of parallax of the image presented by the display device becomes equal to that of the subject image actually captured by the viewer with his or her eyes.
According to the method of Patent Document No. 1, multiple pairs of corresponding points are extracted from those two images captured by the right and left cameras (which will be referred to herein as “right-eye and left-eye images”). And distance information is collected based on the respective pixel locations of those corresponding points. In this case, from some pixel locations in the right- and left-eye images, no corresponding points may be available. However, the image information of such pixel locations with no corresponding points available should be included in any of the two images that have been captured by the right and left cameras. That is why the parallax-corrected image can be further corrected using such image information. Consequently, a stereoscopic image that should look natural to anybody's eyes can be produced by such a method.